1. Field of Invention
The present invention relates to functionalizing the surface of a substrate to impart desirable properties to the surface, and functionalized structures.
2. Brief Description of the Related Art
The current invention has been developed to improve upon inherent deficiencies in the performance of a variety of substrate surfaces. Examples of such deficiencies include but are not limited to:                a) chemisorption of other molecules,        b) reversible and irreversible physisorption of other molecules        c) catalytic activity with other molecules        d) allow attack from foreign species, resulting in a molecular, structural and/or cosmetic breakdown of the substrate surfaces and/or bulk        e) Outgassing of volatile materials (i.e. water vapor and organics) from a substrate under vacuum environments resulting in extensive time required to reach a target vacuum and/or the inability to achieve a target vacuum and/or the inability to maintain a target vacuum        f) buildup of secondary electron emission on a substrate under vacuum environments        g) hydrogen permeation of a substrate under vacuum environments through coating on the inside and/or outside whereas the inner portion is subjected to vacuum.        h) or any combination of (a)-(g)        
There are several known processes that attempt to address the listed deficiencies via a variety of surface treatments. However, a need exists for a process which permits further enhancement of a surface.
There are existing processes which already attempt to alter the surface properties of substrates by: a) depositing multiple layers of amorphous silicon and b) functionalization of a deposited amorphous silicon layer. The purpose of multiple layer amorphous silicon coatings is to protect the treated substrate from corrosive attack and/or to decrease outgassing from the surface under vacuum conditions. A multilayer silicon surface alone, however, may have inadequate inertness and functionality characteristics. By chemically altering the surface through the direct bonding of organic molecules, the surface characteristics can be dramatically altered/improved/tailored to achieve specific surface performance enhancements. Prior art has demonstrated this ability via single-layer silicon depositions followed by surface functionalization; however, this treatment may have insufficient anti-corrosion and/or anti-outgassing performance. By applying a multilayer deposition in conjunction with a chemically tailored composition of the terminal silicon layer, the surface of a substrate may be optimally enhanced to a desired level of performance.
The prior art shows the use of silanes or silicon hydrides to modify surfaces. The present invention utilizes the formation of a hydrogenated amorphous silicon coating on a surface through the decomposition of silanes or silicon hydrides, followed by a secondary process of surface functionalization with a reagent containing at least one unsaturated hydrocarbon group (e.g., —CH═CH2 or —C≡CH). Additional elimination of residual surface defects can be achieved through reagents capable of thermal or chemical disproportionation followed by chemical bonding to these sites, and/or radical quenching.